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UK ESS Installer in Surrey/Home Counties

Hello - I am struggling to find someone who will fit a Victron ESS (Quattro 8 KVA 48V) with 16kWh of BYD batteries. Plenty of PV suppliers willing to charge me £5K plus for the installation (plus another 12k for the kit itself). Anyone know an installer/electrician who can do this in Surrey for a reasonable fee? I am inclined to split the supply of the inverter/charger from the PV as it feels like I am being quoted a fat margin on top of subcontractor fee

Nick Neil-Boss asked
daza commented ·

12 Answers

Does this BOM / Wiring Diagram Look OK?

I just spent an hour typing everything out in detail, hit submit and got an error- doh! So forgive the potential brevity of this 2nd attempt...

I have an existing PV Array and inverter (see the right hand side of the diagram below) and am looking to add battery storage.

Unfortunately the existing PV array configuration is above the Voltage input limit for the EasySolar, but I think I can either split this into 2 strings or I might add another array at a later date. I was also able to find a heavily discounted EasySolar unit, so it seemed like the simplest ("all in one") solution.

I had difficulty at first confirming that the AC-Out doesn't need connecting and the AC-In is in fact bi-directional (I think perhaps it is the PowerAssist feature used to determine what goes back out).

Some of the connections i'm still not 100% sure of, but i've tried to detail what/where on my diagram.

Any advice/tips/tricks would be greatly appreciated- thanks!



Lee Tickett asked

0 Answers

ESS and Grid


i have an ESS configured system (with Multiplus II) and have a question regarding when grid is been used.

From my reading and understanding, Solar energy will be used following this priority:

i. Power Loads connected to AC out then

ii. Charge batteries then

iii. Export excess to grid if so configured

My question is that when utility grid is available and the SOC drops below the configured usage SOC and there is adequate solar energy, the Multi plus will transfer all loads connected to the AC out to grid and use the solar to charge batteries ONLY. My thinking was that since there is adequate solar it should follow the priority list as stated above.

iot asked
gazza commented ·

5 Answers

ESS (AC DC coupled) "Feed-in excess solar charger power" not full potential


i running a ESS (MultiGrid 48/3000 FW459, VenusGX FW v2.31with EM24) with AC Coupled third party PV Inverters (via ET340 and ET112) and a Smart Solar 150/35 v1.39 and a BYD B-Box 5.0kWh. (DVCC enabled, SVS disable, Smartsolar has BMS controlled)

The DC Coupled PV system is oriented south and could be enlarged by approx 900 Wp, since currently only 1,8kWp is installed. Maximum charge power to battery is limited at 2000W fixed due to the 35 Amps - i know ;).

In the ESS Settings I enable " Feed-in excess solar charger power" but soon i discovered the the typical behavior of the system was to charge from the East oriented AC Coupled inverters, which means, the the battery is full, sincce there is enough excess. But the south orientated DC coupled PV System was dearted by over 50% due to battery being at SOC 100%, even with the enable option of "feedin excess DC Power". Over have of the production of the south oriented DC coupled PV is derated (see pic attached, redline is potential solar production).


To prove my hypotheses i changed the ESS Setpoint to activly discharge the battery into the grid, thus a lower SOC than 100% is realized. this enables the BMS controlled Smart Solar to use the full potential of the PV system. (previously 340W production goes up to 900W Production).

See my screenshots and notes

ESS Feed-in excess solar charger power - not full potenial.pdf


I presume that the Mutligrid doesnt discharge/feedin as much power as the full potential of solar available on the DC side.

I would presume that the voltage Gap between SmartSolar and Multiplus isn't high enough for Multi to discharge the battery more but to keep it at 100% and though making it possible for the SmartSolar to feedin more of his potential solar power.

So propably i will not add any more Modules to the Smart Solar or install another SmartSolar, but install another PV Inverter AC coupled.

If anybody has the same Issue please let me know!

If anybody has an idea how to optimize the use of the DC coupled Solar to feed into the grid, please let me know! I thought already of an external PLC writing the ESS Setpoint into the Modbus register, to actively reduce the SOC during the daytime, to make more use of the DC coupled PV System.




ossi asked
ossi commented ·

5 Answers

ess charge power limit doesn't appear to do what I expect

Hi folks. I'm trying to limit the charge current of the batteries on my Multiplus II 48/5000 inverter when using ESS. Inverter running latest firmware.

as you can see, the battery is charging at the rate set in the multiplus VEConfigure tool (30A)



The ESS setting is for the purpose of experimentation set to 100W. But the batteries are still charging at 30A.

Is this a bug, or have I misunderstood something?


Tim Robinson

Basingstoke, UK

gr0mit asked
radon238 commented ·

2 Answers

Victron ESS with a non Victron EV charger

After a Victron ESS installation at home, I am trying to find a solution to use my non-Victron EV charger normally. My new installation has a system configuration that includes a Fronius with a string of solar panels and a Victron (Multiplus + Cerbo + mppt) with a second string + batteries (2 x dyness A48100).

My EV charger (brand Policharger) has 2 AC amperimetric clamps, for dynamic charging according to home loads and PV surplus.


Since the Victron installation the clamps do not measure correctly when the battery is charging or discharging. However, if the batteries are idle the clamps and the EV charger work fine.

As of today, to use the EV charger, I need to manually play and activate the “keep batteries charged” mode or set the SOC target above the current value. Doing this manually every day is not very convenient, so I am looking for a better solution:

  • Should my EV charger be connected in a different way to the Victron ESS?
  • Is there any configuration to automatically detect a high load (EV charger) and then put the battery into idle mode?
  • Any other option?

I got an interesting suggestion to install and use Node-Red, however since I read Node-Red is not supported by Victron, I would like to find other ways. I am assuming the solution to my challenge would be very useful to other new Victron installations where there is a non-Victron EV charger.

Thank you!

enfrafer asked
Tobias Franklin answered ·

6 Answers

[SOLVED] ESS Exporting when export disabled

Can anyone tell my why my system is exporting, even when configured for not to do so?



seriusrod asked
seriusrod commented ·

3 Answers

Grid feeding with Multiplus ii 48/15000 c10/26 lijst synergrid list

I would like to use 3 multiplusses II 48/15000 for ess with mppts rs 450|200.

Is it compatible for the Netherlands or on short term compatible?

Because the specific model is not aknowledged.

The other multiplussen are already in the list en and the quattro range also.

With kind regards, Marc

marc-heide asked
michaelvh edited ·

8 Answers

High grid usage since v500

I've been noticing a high grid usage since version 500 of the MP2 fw.

My system is setup in a ESS zero feed configuration and with a setpoint of 0. The normal grid consumption interval is between 70 and 180w. The house consumption is not that high, normally at 450w, so the grid power usually is a 1/3 of the total consumption.


Also with this problem above, I also noticed that the system always overcharges the battery. I have 14s/13kWh of lithium configured at a max. voltage of 56.8, but it continuously gets charged to 57.4v. I guess that the only thing that prevents it from overcharging it's the BMS that kicks in at 4.09S for balancing.
Configuring DVCC to 56v has no effects. DVCC seems totally inutilized. Current limiting also doesn't work.

Is there any way of opening an issue for this kind of bugs so we can trace them and know if they are being followed or addressed by Victron technicians?

Is there a way of rolling back the MP2 fw to a well-known version?

My system: MP2-5K / 14s-13kWh-57v Lithium / BMS not integrated / Smartshunt / MPPT 150/80 ve.bus connected / Fronius 5K integrated.


When the Max.Charge voltage is set to 56, the battery gets charged up to 56.7. That seems in line with the numbers I got when I had the voltage set to 56.8.


Also I've noticed that when the charge is completed, the grid setpoint offset seems to normalize.
So it seems to me that may be a problem with the ESS charge algorithm mapping. There was plenty sun available during the charge, the system was throttling the Inverter and Charger, but at the same time getting energy from the grid to charge the batteries.


That's insane... no one?


seriusrod asked
seriusrod answered ·

2 Answers

Unexpected grid feedback from Quattro 15000

I have a newly installed Quattro 48/15000 connected with an autotransformer to my house. I brought the grid to the AC in 2 terminals from the meter panel. The autotransformer feeds our house through a panel which has two feeds to sub panels. I also have a battery bank (30KWH EG4 batteries) and an MPPT 450/200 that has 10KW or panels attached.

The inverter has a loud buzzing noise that comes and goes as well as some noise on the AC waveform but this question is about the grid tie. When I throw the breaker enabling the grid connection I hear the relay click and the sound from the unit changes, all expected. What isn’t expected is that the cerbo display shows the grid connection at 50W or so but an additional 3KW of load that is not coming from the house. External measurements have shown this to be exported to the grid but the cerbo knows nothing about this. This even happens if there is no solar and all of the power is coming from the batteries. I have the grid set point at 50w and have turned off export from the dc and ac connected solar chargers in the ESS settings so I’m at at loss to explain what is happening. I can’t leave it connected to the grid when it exports against configuration. This means that if my batteries get too low I will be without power.

Maybe I have something misconfigured? Any ideas about how to fix this would be appreciated.

mkbrandt asked
rickc edited ·

3 Answers

Anyone with a Grid Tied Victron system in Australia or NZ?

Is there anyone in this community that has a Grid Tied Victron system that is subject to the regulation requirements in Australia or New Zealand?

I would like to understand what you did & how it was done.

For example:

  1. Did you have to use a Grid Protection Relay? What Make/Model? Did that satisfy electrical inspection?
  2. Are you doing any grid feed in of excess solar?
  3. Do you have diagram of the install that you are willing to share?
  4. Which Grid Code Selection did you make in VE Config? N-bypass or No N-Bypass? How did that decision impact your distribution wiring or bypass/isolation switching?
  5. Any other features of the install that Victron documentation doesn't cover?

Hoping to start a discussion around what has worked & what doesn't work.

bipedalprimate asked
bipedalprimate commented ·

2 Answers

Multiplus II 48/3000/35-32 and CEC Approval (Australia) - ESS Not Allowed

Multiplus II 48/3000/35-32 Inverter is CEC listed as approved as Stand Alone Inverter With Generator Input Battery Only. This means my local electricity distributor will not allow it to be grid connected in an ESS configuration.

The approval certificate is Certificate SAA181339.pdf.

That certificate shows compliance with:

IEC 62109-1 Ed 1.0,
IEC 62109-2 Ed 1.0,
AS 62477.1:2016 and
AS/NZS 4777.2:2020 Inc A1

The CEC document CEC-inverter_listing_categories_2021.pdf (p2) indicates the Multiplus II 48/3000/35-32 Inverter meets the requirements as a Multiple Mode Inverter and hence approved as a Grid Interactive inverter.

As I have just acquired 2 Multiplus II 48/3000/35-32 in Jan 2022 for use in a parallel ESS system with Fronius inverter on AC1 Out, this has become an issue.

Is there any reason the Multiplus II 48/3000/35-32 Inverter is not listed as a Multiple Mode Inverter?

bipedalprimate asked
svnrex commented ·

4 Answers

Hulp met node red.

Ik ben bezig met node red maar ik vrees dat ik er gewoonweg te weinig van snap.

Voor dat ik heel veel verkeerd doet is mijn vraag, is er iemand in de positie en de mogelijkheid om mij even te helpen met een aantal instellingen.

Ik wil een instelling maken dat mijn grid feed in veranderd door de soc van de batterij.

En ik wil dat er een relai schakeld op de cerbo bij een soc van >95%

En ik wil een relai schakeling maken op basis van temperatuur.

Ik hoor het graag :)

richard-veghel asked
marceldb answered ·

7 Answers

UK regulations ESS vs Offgrid

I am looking to change my LUX ACS 3600/5kw growatt to victron but so far have been told two different things. I have a G98 allowing 5.8kw. I have28kw of pylontechs and wanted to be offgrid as much as I could but charge from it when needed. Have 6kw panels.

I want to divert excess electricity to heating/water (maybe ASHP) but am told it is not permitted to be offgrid in my scenario unless i use a genertor, as the electric can go both ways to and from the grid even though i dont want to sell the energy. Already 2/3 of my PV is going to the grid, partly due to the inflexible Lux which does not allow me to charge discharge batteries when needed - only at specific times which cannot overlap.

I dont understand other than perhaps utilities do not want self sufficiency, why this is, can anyone explain?

Also a quote for an "offgrid system" with a dual switch over consumer unit with 10k MultiPlus 48/10000/70-50 230V Battery Charger Inverter, rs450/100 mppt, with fitting and cabling, most of which is there as are battery disconnects.

Does £7,5k fitted sound a little high to replace the inverter and charge controller?

Andrew asked
daza commented ·

6 Answers

EasySolar-II: MPPT Low Charge Voltage

Hello colleagues. Half a year ago I ran into a problem that I have now managed to solve. I want to leave this here, maybe it will be useful to someone. It would also be great to get official comments from Victron in order to better understand the reasons for what happened.

So, this is a house in the forest, far from civilization. Autonomous system with EasySolar-II GX 3000 with built-in MPPT 250/70 + four AGM batteries of 130 Ah + battery monitor BMV-700 + PV modules 1980 Wp. The system was put into operation at the beginning of 2021.


The system worked great, but two years later a client complained to me that after sunset the system turned off too quickly due to low battery voltage. At first I thought the batteries were dying. But it turned out that even on a sunny day and with minimal consumption, SOC rarely reached 100%, since something was limiting the charge much earlier. As soon as the water heater was turned on, the PV power immediately increased to normal values.

Having studied the charts in detail in the Advanced section, I found that the built-in MPPT incorrectly reads the battery voltage, overestimating it.

Fortunately, there are three devices in the system that measure battery voltage: MPPT, VE.Bus and BMV. The VE.Bus and BMV readings are completely the same, and the MPPT readings are 2.5-3 volts higher. If this only happened during the day, when the MPPT is a generator, one would think that there is a problem in the wiring that is causing the voltage drop. But the MPPT shows a higher battery voltage even at night, which means it's not the wiring.


As a result, the MPPT "thought" it was supplying the correct voltage to the batteries, when in fact it was almost 3 volts lower. From this, the batteries were chronically undercharged. I checked all the settings, everything was correct there. Then I started looking on the charts for the moment when this problem first appeared. It turned out that the minimum difference in readings began about 6 months before the client complained to me about the strange operation of the system. Since then, this difference in the measured voltages has gradually increased, reaching 2.5-3 volts.

The solar controller built into the EasySolar-II is connected to the batteries not directly, but via a board with electronic components. Something must have happened there. I updated the firmware of all system components to the latest versions, but nothing has changed.

Then I created the E-RMA. Victron told me to remotely disconnect the voltage sensor in the inverter as a test, but that didn't help. The case was declared under warranty and I could send the EasySolar to Victron for repair.

The object is far from us, and all transport costs with dismantling and installation would cost our client at least 300 euros, which did not inspire him at all. In addition, we could not leave the client without electricity, because the system is autonomous. So it was necessary to provide a replacement EasySolar, which at that time we did not have.

And now we have a replacement EasySolar, and before organizing the repair, I decided to try to solve the problem remotely again. By this time, the new version of Venus OS 3.00 had just arrived, but the update did not change the situation. Then I reset MPPT to factory settings and set it up again, but that didn't help either, as did rebooting the entire system multiple times. I did many other strange things, even activated the equalization in the MPPT settings for a few seconds, hoping to somehow stir up the MPPT and reset its error: the battery voltage jumped, but the difference was again almost 3 volts.

Then I had the idea to just change the charging voltage settings in the MPPT configuration so that the actual values on the battery would be correct, but this was not a desirable option, because over time the difference can become even greater. And I don't want fake data from MPPT on the charts.

The last thing I decided to try was to take away the MPPT's ability to make decisions on its own by switching it to "External control" mode, and for this you need to install an ESS assistant, which, in general, is not intended for off-grid systems. As soon as I installed the ESS assistant, the problem was immediately solved.


It's hard for me to say why this happened. I can only assume that some components on the board through which the built-in MPPT is connected to the battery did not work properly, but these components do not affect the operation of the MPPT in "External control" mode. Maybe, of course, the problem is in the MPPT itself, but I have never encountered something like this when I installed MPPT separately. It would be interesting to know the views of fellow installers and Victron employees on this matter.

romarub asked
romarub commented ·

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